Why was James not with Peter and John when they went to Samaria?
James was not with Peter and John because he was probably already dead by that time. The normal apostolic pattern was Peter, James, and John together, but only Peter and John are sent from Jerusalem to Samaria in this account.
Les explains that the apostles at Jerusalem heard Samaria had received the Word of God, so they sent Peter and John. He notes that this Philip was not the Philip of the twelve, but likely one of the seven. James was probably already dead, which is why he is not in the midst, since the usual grouping was Peter, James, and John. Therefore only Peter and John went down to Samaria.